* {
  margin: 0;
  padding: 0;
}

.box {
  width: 400px;
  height: 50px;
  border: 1px solid red;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.box .item {
  flex-grow: 1;
  text-align: center;
}
